These rustic little oat-and-apple cakes bake up soft in the middle with golden, crisp edges, and they’re naturally sweetened with apple plus a spoon of sugar substitute. The base is simply oat flour (ground oats), yogurt, and an egg white for lift, with cinnamon and vanilla for that cozy “baked dessert” feel—no regular flour needed. If you like easy, not-too-sweet treats for breakfast or an afternoon snack, this one is a good fit. For another no-sugar, no-flour idea to keep in your back pocket, I also like this healthy dessert without sugar and flour for variety.
Why This Recipe Is Helpful
- Uses pantry basics (oats, yogurt, egg) and one apple.
- Bakes quickly and doesn’t require shaping individual cookies or muffins.
- Sweetness is adjustable, and the walnut topping adds crunch and staying power.
Best For
Anyone who wants a simple baked treat that feels lighter than most cakes and works as breakfast, snack, or dessert.
Be Careful If
This recipe contains dairy (yogurt, butter) and nuts (walnuts, almond flakes). It’s also fairly high in fiber from the oats, which can feel heavy for some in large portions.
Ingredients
For the oat cake base
- 1 small apple, grated (about 3/4 cup / 90–110 g grated apple)
- 1 large egg, separated
- 1/4 cup (60 ml) plain yogurt (unsweetened)
- 1 tablespoon (14 g) coconut oil, melted
- 1 to 1 1/2 cups (100–150 g) oat flakes, ground into oat flour
- 1 teaspoon (5 g) baking soda
- Pinch ground cinnamon
- 1/2 teaspoon (2.5 ml) vanilla extract
- 1 teaspoon (5 ml) lemon juice (a splash)
- 1 tablespoon sugar substitute (about 10–15 g, depending on brand)
For the center and topping
- 1 tablespoon (14 g) butter, cut into small pieces
- 1 small handful walnuts, chopped (about 1/4 cup / 25–30 g)
For the filling glaze
- 1 egg yolk
- 1 teaspoon (5 ml) milk
- Sprinkle of almond flakes (about 1 tablespoon / 5–7 g)
Ingredient Notes
- Oat flour: Grind rolled oats in a blender until fine; stop and stir once so it’s evenly ground.
- Yogurt: Plain yogurt gives tenderness; thicker Greek-style yogurt works too (the dough may be slightly stiffer).
- Apple: Grate it finely so it melts into the batter; a crisp apple (like Gala or Pink Lady) bakes up nicely.
- Sugar substitute: Use one you like the taste of; sweetness levels vary a lot by brand, so adjust to your preference.
Kitchen Tools Needed
- Box grater
- Mixing bowls (2)
- Whisk or fork
- Baking sheet
- Parchment paper
- Spoon or spatula
- Small bowl (for yolk + milk)
Step-by-Step Instructions
- Heat the oven. Preheat to 350°F (180°C). Line a baking sheet with parchment paper.
- Grate the apple. Grate the apple into a large bowl. If it’s extremely juicy, lightly squeeze out just a little liquid (don’t dry it out completely—moisture helps the texture).
- Mix the base (egg white batter). Add the egg white, yogurt, melted coconut oil, oat flour (start with 1 cup/100 g), baking soda, cinnamon, vanilla, lemon juice, and sugar substitute. Stir until you have a thick, spreadable dough.
- Adjust thickness. If the mixture feels loose or wet (it should mound on a spoon, not pour), stir in more oat flour a few tablespoons at a time, up to the full 1 1/2 cups (150 g). Let the dough sit 3–5 minutes so the oats hydrate; it will firm up slightly.
- Make the yolk glaze. In a small bowl, whisk together the egg yolk and milk until smooth.
- Shape on the pan. Spoon the oat dough onto the parchment and spread into a rustic oval or round about 3/4-inch (2 cm) thick. Leave a slightly thicker rim around the edges.
- Add filling and toppings. Spoon the yolk glaze into the center area (not over the rim). Dot with butter, then sprinkle on walnuts and a sprinkle of almond flakes.
- Fold the edges. Gently fold the outer edge inward a bit to create a casual border that helps hold the center.
- Bake. Bake for 18–22 minutes, until the edges look golden, the center looks set (not wet), and it smells toasty. If the top is browning too fast, tent loosely with foil for the last few minutes.
- Cool slightly, then serve. Let it rest 10 minutes so it firms up and slices more cleanly. Serve warm or at room temperature.
Pro Tips
- Letting the mixed dough sit for a few minutes prevents a gummy center because the oats absorb moisture.
- Spread the base slightly thicker than you think; too thin can make it dry and brittle.
- If your yogurt is very thin, you’ll likely need closer to 1 1/2 cups (150 g) oat flour.
- For neat slices, cool for 15–20 minutes before cutting.
Lighter Swaps
- Use low-fat plain yogurt instead of full-fat.
- Reduce the butter to 1 teaspoon (5 g) and rely on walnuts for richness.
- Skip the almond flakes if you want a simpler topping (the walnuts are enough).
Common Mistakes
- Not adjusting the oat flour: Apple size and yogurt thickness vary; a too-wet batter won’t set nicely.
- Overbaking: Oat-based bakes can go from tender to dry quickly—pull it when the center is set.
- Spreading too thin: A thin layer bakes like a cracker instead of a soft cake.
Serving Suggestions
Slice and serve as-is, or add a spoon of extra yogurt on the side. It’s also nice with tea or coffee when you want something lightly sweet.
Storage Instructions
Store leftovers in an airtight container in the fridge for up to 3 days.
Reheating Tips
Warm in a 300°F (150°C) oven for 6–8 minutes (best for keeping the edges crisp), or microwave briefly just until warmed through.
Nutrition Estimate
Per serving (assuming 4 servings):
- Calories: ~210–260
- Protein: ~7–9 g
- Carbs: ~20–28 g
- Fat: ~11–15 g
Values are estimates and may vary by ingredients and portion size.
Recipe Summary
- Prep Time: 10 minutes
- Cook Time: 20 minutes
- Total Time: 30 minutes
- Servings: 4
- Cuisine: European-inspired
- Course: Breakfast/Snack/Dessert
- Calories: ~210–260 per serving
Frequently Asked Questions
Can I use rolled oats without grinding them?
Grinding gives the best “cake-like” texture. If you leave them whole, the result is chewier and can crumble more, but it will still bake.
What sugar substitute works best here?
Use a granulated 1:1 substitute you already like the flavor of. If yours is much sweeter than sugar (like some stevia blends), start with less and adjust next time.
Can I make this nut-free?
Yes—skip the walnuts and almond flakes. The bake will be less crunchy on top, but it still works.
Conclusion
This is an easy, wholesome-feeling bake that turns simple oats, yogurt, and a grated apple into a tender snack cake with crisp edges. It’s lightly sweet, flexible, and great when you want something homemade without a lot of fuss.